ABSTRACT The Cytometry and Antibody Technology (CAT) Facility?s mission is to support the community of researchers at the University of Chicago with: 1) cutting-edge technology operated by expertly trained personnel; 2) high- quality analytical monoclonal antibodies; and 3) expert technical consultation and training of researchers. The Facility is utilized by University of Chicago Medicine Comprehensive Cancer Center (UCCCC) investigators conducting basic and translational research of cellular phenotype and function. The CAT Facility serves the UCCCC membership by providing tools necessary to measure the properties of cells and their products. This includes the technology and staff expertise to use these reagents for experimental measurements (flow cytometers, mass cytometer, image cytometers, cell sorters and multiplex analyzers), as well as reagents used to label the cells (antibody/hybridoma bank that provides commonly used, highest quality purified antibodies, purification of existing monoclonals, and fluorescently coupled antibodies). Multiparameter analysis of single cells has become a standard tool in cancer research. Flow cytometry technology now allows for the measurements of more than 15 different markers simultaneously. With imaging flow cytometry (e.g., Amnis ImageStream), the CAT Facility can also capture images of the analyzed cells and develop clinical or research assays based on the expression of these markers as well as on their distribution. With mass cytometry, more than 40 parameters on a single cell can be measured to obtain an unequalled amount of information for each and every cell analyzed. Specific Core accomplishments during the current funding period include obtaining a new BD FACsFortessa for 15 color flow cytometry, an Aria Fusion for sorting human samples for translational studies, and a new CyTOF Helios mass cytometer that was funded by a successful NIH S10 award. The Facility?s Scientific and Technical Directors provide direct oversight of the operation of the CAT Facility. A Faculty Oversight Committee (FOC) also provides an advisory role to the Facility personnel with regards to services, scientific direction and fiscal issues. The Office of Shared Research Facilities (OSRF) serves as the home department for the Facility, providing IT and HR support, accountancy services, and strategic planning. The Research Resources Oversight Committee (RROC) is a faculty committee that provides scientific and financial oversight of all BSD Cores, and provides long-term strategic planning of Core services and resources. Future plans for the CAT facility include improving direct contact with the research community to present information about the Facility and better understand the needs of our user base, development of CyTOF panels and reagents, and advancing as a cutting edge facility by incorporating new technology, while providing our successful base core services.